'xianyutuci'
ass Screen(object) :
    @property
    def width(self) :
        return self._width

    @width.setter
    def width(self,valuer) :
        if not isinstance(valuer,int):
            raise ValueError('score must be an integer')
        if valuer < 0 :
            raise ValueError('score must over zero')    
            self._width=valuer

    @property
    def height(self) :
        return self._height
    @height.setter
        def height(self,numbe) :
            if not isinstance(numbe,int) :
                raise ValueError('score must be an integer')
            if numbe < 0 :
                raise ValueError('score must be an zero')
                self._height = numbe
    @property
    def resolution(self):
        return self._width * self._height
s=Screen()
s.width = 1024
s.height = 768
print(s.resolution)
